Alkylxanthates and use of alkylxanthates in the integrated pest management

ABSTRACT

This invention relates to novel alkylxanthates of formulae 1 to 3 and use of alkylxanthates of formulae 1 to 6 in the integrated pest management, more specifically alkyl xanthates are used as insect growth regulatory for pest management in agricultural fields no or less environmental impact.

FILED OF THE INVENTION

[0001] The present invention relates to novel alkylxanthates of formulae1 to 3 and use of alkylxanthates of formulae 1 to 6 in the integratedpest management, more specifically alkyl xanthates are used as insectgrowth regulators for pest management in agricultural fields no or lessenvironmental impact.

BACKGROUND AND PRIOR ART REFERENCES

[0002] Many small scale farmers are illiterate and believe in the usageof high volumes, high pressure, and high doses of pesticide as the mostsuitable way of crop protection, these practices have resulted in manyenvironmental problems such as effect on non-target species, pesticideresidue accumulation, variable selectivity, development of resistant inpests, ecological imbalance by elimination of natural predators as wellas and environment pollution. More than 50% of the pesticides used inthird world countries are globally banned and 95% of the used by thepublic health sector also find restricted use in other nations (Newscorner, Pesticide World, 1998). There are 33 pesticides, which have beenbanned in advanced countries, but they are allowed to be imported andused in third world countries (Insecticides Act, 1968 and Indian ExpressNewspaper January, 2000). In order to restrict the use of bannedpesticides, they must be replaced with suitable pesticides that must betarget specific, non-toxic to other species, easily biodegradable andless persistent. Hence, the advanced countries are mainly concentratedto identify the IV generation of insecticides, which are highlyeffective and generally selective agents derived for tactical skills. Itrequires more management expertise which am far friendlier to the totalenvironment including the biological control organisms.

[0003] The applicants have isolated a Ethylene Bis (isobutyl xanthate)(1) from a green alga Dictyosphaeria favulosa (Venkateswarlu et al.,1993). It was tested agaisnt various aquatic stages of Aedes aegypimosquito, which is a yellow fever vector. The compound 1 exhibitedlarvicidal and insect growth regulatory activity in dose dependentmanner (Venkateswara Rao et al., 1995). Around thirty-five analogueswere synthesised and tested against agricultural polyphagouslepidopteron pests. Among them four analogues have been identified asgood antifeedant and insect growth regulators. Two of the compounds fromthe four analogues are totally new structures and remaining two arestructurally known but the activity was identified for the first time. 1

Compound I Ethylene Bis(isobutylxanthate) Physical state Colorless solidM.P. 40-42° C. Molecular C₁₂H₂₂O₃S₄ formula EIMS (70 eV) m/z 326Elemental Found: C 44.15%, H 6.90%, S 39.15% analysis Required: C44.13%, H 6.79%, S 39.28% IR (KBr) ν_(max)(KBr) 2950, 1465, 1235, 1200,and 1140 cm⁻¹ UV (MeOH) λ_(max)(MeOH) 217(ε 12735), 233(14766) and 278nm (20048) ¹H-NMR (CDCl₃, 200 MHz) δ 1.0(6H, d, J=7.5 Hz), 2.13(1H, m),3.42

[0004] In 1950 S. V. Zhuravlev, reported the synthesis of ethylenedixanthates (2-5). Heating the mixture of 4.7 gms (CH₂Br₂)₂ and EtOCS₂Kin ethanol on a steam bath gave ethylene dixanthate (yield 90%). Inwhich compounds 2 and 5 possess a moderate insecticidal activity againstlice.

[0005] In 1954 Yamasaki, reported the synthesis of organophophoruscompounds (xanthgenates). A series of xanthogenates (6-10) weresynthesized in three ways. A)

B)

C)

here M = alkali metal 6 R′ = Me; R = Me 7 R′ = n-propyl; R = ethyl 8 R′= ethyl; R = ethyl 9 R′ = isopropyl; R = ethyl 10 R′ = n-butyl; R =ethyl

[0006] In 1950 S. V. Zhuravlev, reported the synthesis of p-xylenedixanthates. MeOCS₂K reacted with p-C₆H₄(CH₂Cl)₂ in ethanol gavep-xylene bis (methylxanthate) (yield 75.5%). A series of p-xylene bisxanthates has been synthesized (11-20). All these bis xanthates areinsecticides with low order of activity.

11 R = ethyl 12 R = n-butyl 13 R = isobutyl 14 R = octyl 15 R = isooctyl16 R = nonyl 17 R = decyl 18 R = cyclohexyl 19 R = phenethyl 20 R =benzyl

[0007] The dixantihates were dissolved in refined kerosene to form a 25%solution was used as a efficient defoliants for cotton plants (Cupery,1958).

[0008] Etylene Bis (isopropylxanthate) (21) and ethylenebis(isobutylxanthare) (1) were used as noncorrosive antiseizelubricating oil additives (Khalikov and Vinogradova, 1964).

1 R = isobutyl 21 R = isopropyl

[0009] Methylene bisxanthates are used as collector reagents in thefroth flotation or sulfide minerals (Saphores, et al., 1991).

[0010] Ten newly synthesized organo phosphorus derivatives containingalkyl xanthates were tested for their antifungal activity againstColletotrichum falcatum, Fusarium oxisporium, Curvularia pallescens(sugarcane pathogens). The O,O-diethyl thio phosphate derivativesexhibited 100% mycelial inhibition against all the test fungi at 1000ppm. All thio phosphate derivatives showed fungistatic effects atminimum inhibitory concentration of 1000 ppm. These derivatives alsoproved better than correctly used synthetic fungicides (Senguptha etal., 1998).

[0011] In the course, the applicants have synthesized ethylene bis(isobutylxanthate) and its analogues. In which compound 25, 27 and 28are newly synthesized compounds and these compounds were tested forantifeedant and larvicidal activities.

OBJECTS OF THE INVENTION

[0012] The main object of the invention is to provide novelalkylxanthates for agricultural applications.

[0013] In another object of the invention is to provide a new use ofnovel alkylxanthates for use in integrated pest management.

[0014] In still another object is to provide a new activity ofalkylxanthates for use in integrated pest managements.

[0015] In yet another object is to provide a process for the preparationanalogues of alkyl xanthates useful as an antifeedent and as insectgrowth regulators.

[0016] In yet another object is to provide a composition useful as aninsect growth regulator and antifeedant for the integrated pestmanagement.

SUMMARY OF THE INVENTION

[0017] The present invention rates to novel alkyxanthates of formulae 1to 3 and use of alkylxanthates of formulae 1 to 6 in the integrated pestmanagement, more specifically alkyl xanthates arm used as insect growthregulators for pest management in agricultural fields no or lessenvironmental impact.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[0018]FIG. 1 shows structure of Methylene bis(tetrahydrofurfurylxanthate.

[0019]FIG. 2 shows structure of m-Fluorobenzyl n-butylxanthate

[0020]FIG. 3 shows structure m-Fluorobenzyl isobutylxanthate

[0021]FIG. 4 shows structure Ethylene Bis (isobutylxanthate

[0022]FIG. 5 shows structure of Methylene bis (n-butylxanthate)

[0023]FIG. 6 shows structure p-Xylene bis (n-butylxanthate)

[0024]FIGS. 7 and 8 shows glimpses of the results.

DETAILED DESCRIPTION OF THE INVENTION

[0025] The present invention particularly relates to develop anAlkylxanthates as novel Insect Growth Regulators (IGR's) that are usefulfor integrated pest management. The alkylxanthates employed in thepresent invention was useful to maximize the lepidopteron pestinfestation in agricultural fields with no or less environmental impact.These alkylxanthates as natural products are relatively uncommon innature. We have been isolated a Ethylene Bis (isobutylxanthate) (1) froma green alga Dictyosphaeria favulosa. It was tested against variousaquatic stages of Aedes aegypti mosquito, which is a yellow fevervector. The compound 1 exhibited larvicidal and insect growth regulatoryactivity in dose dependent manner. The analogues of Alkylxanthates hasbeen proved as insect growth regulator (IGR) against two differentlepidopteron pests (Spodoptera litura and Helicoverpa armigera), assimilar to Azadiractin (standard compound) a natural product isolatedfrom neem seed kernel. They have simple structures unlike Azadiractinand possessing same kind of mode of action, which can be synthesizedeasily in the laboratory

[0026] The present invention provides three novel compounds ofalkylxanthates namely

[0027] (i) methylene Bis (tetrahydrofurfuryl xanthate)

[0028] (ii) m-Fluorobenzyl n-butylxanthate and

[0029] (iii) m-Fluorobenzyl isobutylxanthate having the structuralformulae as shown in FIGS. 1, 2 and 3 respectively of the accompanyingdrawings, for use in agricultural applications.

[0030] In an embodiment of the said compounds having the followingproperties on lepidopteron pest as

[0031] (a) larvicidal,

[0032] (b) antifeedant, and

[0033] (c) insect growth regulator.

[0034] In still another embodiment the novel compounds possess toxicitytowards brine shrimps and mosquitoes.

[0035] In still another embodiment of the invention, the novel compoundscontrols the growth of the agricultural pests Spodoptera ittura, andHelicover armigera.

[0036] In yet another embodiment the novel compounds used as insectgrowth regulator is ranging from 50 μg to 100 μg per insect, (topicalapplication on III instar larvae) and 5 to 25 μg oral feeding.

[0037] In yet another embodiment the larval mortality rate is in therange between 50 to 90% when the above novel compounds are used.

[0038] In yet another embodiment of the invention, the amount of analogsof alkyl xanthates used for protecting the leafs are in the rangebetween 15 to 50 micro grams per sq.cm of the leaf area.

[0039] In yet another embodiment, the novel compound methylene Bis(tetrahydrofurfuryl xanthate) is a colorless liquid and the molecularformula is C₁₃H₂₀O₄S₄ and having the following properties: Physicalstate: Colorless liquid Molecular formula: C₁₃H₂₀O₄S₄ ¹H NMR: (CDCl₃,200 MH_(z)) δ1.70 (2H, m), 1.95 (2H, m), 3.71 (2H, m), 4.20 (1H, m),4.55 (2H, t) and 4.78 (1H, s). IR (Neat): ν_(min) (KBr) 2920, 1470,1235, and 1140 cm⁻¹ EIMS (70 eV): m/z 368 UV (MeOH): λ_(max) (MeOH) 217(ε 11150), 242 (1650), 270 nm (19160)

[0040] In yet another embodiment of the present invention, the novelcompound m-fluorobenzyl n-butylxanthate is a pale yellow liquid havingmolecular formula C₁₂H₁₅FOS₂ and having the following properties:Physical state: Pale yellow liquid Molecular formula: C₁₂H₁₅FOS₂ ¹H NMR:(CDCl₃, 200 MH_(z)) δ1.0 (3H, m), 1.42 (2H, m), 1.75 (2H, m), 4.60 (2H,t, j = 7.0 Hz), 4.35 (2H, s) and 6.95-7.20 (4H, m). IR (Neat): ν_(max)2960, 2931, 1615, 1590, 1460, 1240 and 1045 cm⁻¹ EIMS (70 eV): m/z 258UV (MeOH): λ_(max) 210 (ε 37105), 218 (35660) and 280 nm (27354)

[0041] In yet another embodiment of the invention, the novel compoundm-fluorobenzyl isobutylxanthate is a pale yellow liquid and havingmolecular formula C₁₂H₁₅FOS₂ and having the following properties:Physical state: Pale yellow liquid Molecular formula: C₁₂H₁₅FOS₂ ¹H NMR:(CDCl₃, 200 MH_(z)) δ1.0 (6H, d, J = 7.0 Hz), 2.12 (1H, m), 4.34 (4H,brs), and 6.92-7.22 (4H, m). IR (Neat): ν_(max) 2964, 2937, 1620, 1585,1472, 1230, 1165 and 1030 cm⁻¹ EIMS (70 eV): m/z 258 UV (MeOH): λ_(max)214 (ε 37190), 220 (35674), and 274 nm (27378)

[0042] One more embodiment of the invention provides a new use ofanalogues of alkylxanthates of formulae 1 to 6 of the drawings as insectgrowth regulators for the integrated pest management (IPM) and theanalogues of alkylxathates used are ethylene bis(isobutyl xanthate),methylene bis (n-butyl, xanthate), methylene bis(tetrafurfurylxanthate), p-xylene bis (n-butylxanthate) andm-Fluorobenzyl isobutylxanthate, the structural formulae of the abovecompounds are shown in the FIGS. 4, 5, 1, 6, 2 and 3of the drawingsrespectively.

[0043] In still another embodiment of the invention, the alkyl xanthatecontrols the growth of the agricultural pests is Spodoptera litura, andHelicover armigera.

[0044] In still another embodiment the amount of alkylxanthates used asinsect growth regulator is ranging from 50 μg to 100 μg per insect.(topical application on III instar larvae) and 5 to 25 μg oral feedingand the larval mortality rate is in the range between 50 to 90%

[0045] In yet another embodiment the analogues of alkylxanthates areused as an antifeedant for the integrated pest management.

[0046] In yet another embodiment the amount of analogues of alkylxanthates used for protecting the leafs are in the range between 15 to50 micro grams per sq.cm of the leaf area.

[0047] In yet another embodiment the analogues of alkylxanthates usedare ethylene bis(isobutyl xanthate),menthylene bis (n-butyl xanthate),methylene bis (tetrafurfurylxanthate), p-xylene bis (n-butyl xanthate)and m-Fluorobenzyl n-butylxanthate and m-Fluorobenzyl isobutylxanthate.

[0048] In yet another embodiment of the invention, the alkyl xanthateacts against the ploy phagous pests, spodotera litura (Tabacocaterpillar) and controls the consumption of the leaf by the pests.

[0049] In further embodiment the present invention provides a processfor the preparation of analogues of alkyl xanthates useful as anantifeedant and as insect growth regulators, said process comprising:

[0050] (a) refluxing, KOH with an alcohol followed by addingcarbondisulphide to get a yellow crystalline compound namely potassium—O-alkylxanthate,

[0051] (b) reacting the potassium-O-&ikyiithaic in the presence ofketone with a bromide derivative selected from methylene di bromide,ethylene di bromide, p-Xylene dibromide or m-flurobenzyl bromide,filtering and removing the ketone under reduced pressure to obtaincorresponding alkylxanthate compounds with the yield ranging from 70 to80%.

[0052] In still another embodiment refluxing is carried out at a 0° C.

[0053] In one more embodiment of the invention provides a novelcomposition used as an insect growth regulator and an antifeedant forthe integrated pest management, said composition comprising an effectiveamount of alkylxanthate and analogues of alkylxanthates with anadditive.

[0054] In still another embodiment the analogues of alkyl xanthate isselected from ethylene bis(isobutyl xanthate), methylene bis (n-butylxanthate), methylene bis (tetrahydrofurfuryl xanthate), p-xylene bis(n-butyl xanthate), m-Fluorobenzyl n-butylxanthate and m-Fluorobenzylisobutylxanthate or mixture thereof.

[0055] In still another embodiment the additive is a solvent, i.e. C₉,cycloxonone, acetone, ethyl methyl ketone etc., with emulsifierpiperonyl butoxide (5%).

[0056] In yet another embodiment, the ratio of the additive to theactive ingredients is in the ratio ranging from 80 to 95%.

[0057] In yet another embodiment, the amount required for controllingthe antifeedant activity is 30 to 60 μg/sq.cm.

[0058] In yet another embodiment, the amount required for use as insectgrowth regulators activity is 50 to 100 μg/insect (Topical) or 5to 25 μgoral feeding.

[0059] The following examples are given merely to understand theinvention clearly and these examples should not be construed to limitthe scope of invention in any manner.

EXAMPLES

[0060] Preparation of bis (alkylxanthates): Into a 100-ml round-bottomedflask, lifted with a reflux condenser, placed 1.05 gm (0.0187 mol) ofKOK pellets was added excess amount (0.007 mol) of alcohol and thereaction mixture was refluxed for 1 hr. The reaction mixture was cooledand decanted the liquid from the residual solid into another dry 100-mlR.B flask. To this cold reaction mixture 1.37 gm (0.0187 mol, 1.08 ml)of carbon disulfide was added slowly with constant stirring to yieldyellow crystalline compound potassium-O-alkylxanthate (yield 80-90%).

[0061] To the above potassium-O-alkylxanthate (0.01 mol) in a 50 ml ofacetone was added methylenedibromide 0.869 gm (0.348 ml, 0.005 mol) orethylenedibromide 0.939 gm (0.52 ml, 0.005 mol) and refluxed for onehour. The reaction sets in within 15 minutes and the yellow reactionmixture becomes white owing to the separation of KBr. Then the reactionmixture was filtered, acetone was removed under vacuum. After usualworkshop

[0062] afforded bis (alkylxanthate) (yield 75 to 90%) showed in Table 1.TABLE 1 Compound No. Compound Name R η I Ethylene Bis(isobutylxanthate)Isobutyl 2 22 Methylene Bis(n-butylxanthate) n-butyl 1 23 EthyleneBis(2⁰-butylxanthate) 2⁰-butyl 2 24 Methylene Bis(2⁰-butylxanthate)2⁰-butyl 2 5 Ethylene Bis(benzylxanthate) Benzyl 2 3 EthyleneBis(n-butylxanthate) n-butyl 2 25 Methylene Bis(tetrahydrofurfurylTetrahydro 1 alcohol) furfuryl

Here R = alkyl group

[0063] Here R=alkyl group

[0064] Preparation of p-xylene bis (alkylxanthates): A mixture ofpotassium-O-alkylxanthate (0.01 mol) and p-xylene dibromide (0.005 mol)in a 50 ml of acetone refluxed for one hour. The reaction sets in within15 minutes and the yellow reaction mixture becomes white owing, to theseparation of KBr. Then the reaction mixture was filtered, acetone wasremoved under vacuum. After usual workup yielded P-xylene bis(alkylxanthate) (yield 75-85%) showed in Table 2. TABLE 2 Compound No.Compound Name R 12 p-Xylene Bis (n-butylxanthate) n-butyl 26 P-XyleneBis (2⁰butylxanthate) 2⁰-butyl

[0065] Preparation of m-fluorobenzyl alkyixanthates: A mixture ofpotassium-O-alkylxanthate (0.01 mol) and m-fluorobenzyl bromide (0.01mol) in a 50 ml of

[0066] Here R=alkyl group acetone refluxed for one hour. The reactionsets in within 15 minutes and the yellow reaction mixture becomes whiteowing to the separation of KBr. Then the reaction mixture was filtered,acetone was removed under vacuum. After usual workup yieldedm-fluorobenzyl alkyixanthates (yield 70-80%) showed in Table 3.03. TABLE3 Compound No. Compound Name R 27 m-Fluorobenzyl (n-butylxanthate)n-butyl 28 m-Fluorobenzyl (isobutylxanthate) Isobutyl

[0067] Preparation of organophophorus compounds: A mixture ofpotassium-O-alkylxanthate (0.01 mol) and O,O-diethyl thio phosphonylchloride (0.01 mol) in a 50 ml of acetone refluxed for one hour. Thereaction sets in within 15 minutes and the yellow reaction mixturebecomes white owing to the separation of KCl. Then the reaction mixturewas filtered, acetone was removed under vacuunl After usual workupyielded O,O-dethyl thiophosphate alkylxanthate (yield 70-80%) showed inTable 3.04.

[0068] Here R=alkyl group, aryl group TABLE 4 Compound No. Compound NameR 29 O,O-diethyl thiophospate Isobutyl isobutylxanthate 30 O,O-diethylthiophospate 2⁰- 2⁰-butyl butylxanthate 10 O,O-diethyl thiophospate n-n-butyl butylxanthate 31 O,O-diethyl thiophospate . . . Phenethyl . . .phenethylxanthate

[0069] Biological Activities

[0070] Methodology for LARVICIDAL Activity:

[0071] To determine the efficacy of different analogues ofAlkyixanthates against mosquito larvae, standard procedures asrecommended by World Health Organization (1981) were followed with minormodifications. The desired concentration of the test solution wasobtained by adding 1 ml of an appropriate stock solution to 249 ml oftap water in 500 ml beaker. Test solutions of different concentrationswere prepared by diluting the stock solution in dechlorinated andfiltered tap water followed by thorough mixing. Tween—80 [Poly(oxyethylene)_(n)—sorbitan monooleate] was used as an emulsifier at theconcentration of 0.002% (v/v) to the final test solution wheneverrequired Control solutions were prepared in tapwater using acetone orethanol and Tween—80 (0.002%). To each of the test concentrations, 25late third or early fourth instar larvae which were acclimatized earlierwere added At least three replicates of each of the tests were made.Based on the results, five to ten suitable concentrations, whichproduced 10 to 100% mortality, were selected for detailed study and forcalculating LC₅₀ values. Mortality was observed 24 hours after exposingthe larvaeto test solutions and the data was corrected for controlmortality if any, by using Abbot's formula (Abbot 1925). All tests werecarried out at a room temperature maintained at 28±1° C.

[0072] Methodology For Developmental Inhibition On Mosquitoes:

[0073] The developmental inhibition potential of different analogues ofAlkylxanthates a evaluated based on the method of Mulla et al., 1974.Experiments were carried out with second, third, fourth instar larvaeand pupae. Initially, to each of the 500 ml beakers containing widerange of test concentrations, 25 larvae were added. Based on theresults, five to ten suitable concentrations, which produced 10 to 100%growth inhibition, were selected for detailed study. The data of atleast three to four replicates each of three separate experiments wassubjected to statistical analysis. Observations on abnormalities inlarvae, pupae and adult emergence were made until 100% emergence incontrols. All the experiments were performed at room temperature.

[0074] BRINE SHRIMP BIOASSAY:

[0075] Brine shrimp (Artemiasalina) eggs were hatched in a shallowrectangular dish filled with artificial seawater, which was preparedwith commercial salt mixture and double distilled water. A plasticdivider with several 2-mm holes was clamped in the dish to make twounequal compartments The eggs were sprinkled into the larger compartmentthat was darkened, while the smaller compartment was illuminated. After48 hours the phototropic nauplil were collected by pipette from thelighted side, being separated by the divider from their shells.

[0076] Twenty shrimps were transferred to each sample vial andartificial seawater was added to make 5 ml. The nauplii can becountedmicroscopically in the stem of the pipette against a lighted background. A drop of dry yeast suspension (3 μg in5 ml artificial seawater)was added as food to each vial (Meyer, at al., 1982). Survivors werecounted with the aid of a 3×magnifying glass, after 24 hours, and thepercent mortality at each concentration and control was determined. The24 hour counts were more useful. During control deaths, the data wascorrected using Abbot's formula.

[0077] STATISTICAL ANALYSIS

[0078] The average mortality and growth inhibition dataofexperiments wassubjected to IBM AT 386 computer analysis at our laboratory forcalculating LC₅₀, LD₅₀, EC₅₀, ED₅₀,etc., and other statistical data Thesoftware used was developed by Reddy et al., 1992.

[0079] Methodology for Antifeedant activity: Tobacco caterpillar,Spodoptera litura F., larvae will be reared on Ricinus cummunis L.leaves at 27° C. and 65-70% RH. Known area (cm²) of leaf disks werepainted with exact amount of pure compound (dissolved in acetone) andwere dried at room temperature till the carrier solvent evaporated Foreach concentration 5 to 6 replicates were prepared and experiments wereconducted individually. Control disks were dipped in caiier solvent(acetone) alone. Third instar larvae weighing 200-250 mg are selectedfrom stock culture, starved for 4 hr, and will be used individually forthe assay of antifeedant activity. After 12 and 24 hours, leaf areameier was used to measure the consumed area of treated and untreatedleaves. Based on the data the percent protection of individual compoundwas calculated. All these properties were compared with well-knownantifeedant isolated from neem kernal ‘Azadiractin’. Control and testlarvae are transferred on fresh leaves and monitored till adultemergence to study the growth and behavioral aspects of the insect.

[0080] Methodology for Growth regulatory activity: In continuation toAntifeedant experiments, the larvae (leaf consumed along withcompound-calculated) were individually monitored till adult emergence.Based on the formation of normal, abnormal pupae, normal adult emergenceand abnormal adult emergence were recorded and calculated the growthregulatory activity of the compound in comparison with standard.Relative inhibition 50 values of alkyixanthates on spodoptera litura andHelicoverpa armigera were statistically analysed.

[0081] Results

[0082] 1. Larvicidal activity of xanthates and its analogues against IVinstar larvae of Aedes aegypti LC₅₀ ± S.E. S. No. Compound (mg/l) 1.Ethylene bis (isobutylxanthate) 8.06 ± 0.22 2. Methylene bis(n-butylxanthate) 5.33 ± 0.97 3. Methylene bix(tetrahydrofurfurylxanthate) 3.77 ± 0.59 4. p-Xylene bis(n-butylxanthate) 7.35 ± 0.51 5. m-Fluorobenzyl n-butylxanthate 12.53 ±1.24  6. m-Fluorobenzyl isobutylxanthate 11.78 ± 2.35 

[0083] II. Developmental Inhibition activity of xanthates and itsanalogues against third instar larvae of Aedes aegypti

[0084] The sub lethal concentrations of all theanalogues [LC₁₀ to LC₂₀concentrations] have exhibited developmental inhibition on mosquito,Aedes aegypti. Abnormal pupalformation and pupal caso attachment toemerged adults (leads to mortality) were quite common most of thexanthates.

[0085] III. Toxic activity of xanthates and its analogues against Brineshrimp, Artemia salina LC₅₀ ± S.E. S. No. Compound (mg/l) 1. Ethylenebis (isobutylxanthate) 25.78 ± 2.90  2. Methylene bix (n-butylxanthate)34.65 ± 3.91  3. Methylenebix (tetrahydrofurfurylxanthate) 5.63 ± 0.624. p-Xylene bix (n-butylxanthate) 45.23 ± 5.63 5. m-fluorobenzyln-butylxanthate 19.00 ± 2.83  6. m-Fluorobenzyl isobutylxanthate 22.54 ±3.26  7. Standard ‘Chamtothecin’ 2.53 ± 0.43

[0086] IV. Antifeedant activity of xanthate and its analogues againstlate third instar of Spodoptera litura Concentration Percent requiredfor 50% leaf Compound Conc. leaf consumption protection code in μg/sq.cm. 12 hr 24 hr A.I EC₅₀ in μg/cm² ± S.E. Standard 20 4.2 12.7 76.426.34 ± 1.77 Azadiractin 15 16.4 27.6 54.98 10 18.6 33.3 48.09 5.0 33.757.2 24.84 Ethylene Bis 65 9.3 25.2 58.07 42.46 ± 5.76 (isobutylxanthate) 50 22.4 45.9 34.85 35 36.1 62.7 20.48 20 60.2 80.78.14 Methylene Bis (n- 30 -0- 7.5 85.37 17 11 ± 1 36  butylxanthate) 253.5 20.7 64.22 20 22.5 45.6 35.14 15 35.2 60.4 22.27 10 48.5 85.1 5.50Methylene Bis 50 22.1 45.5 35.23 37.21 ± 9.67  (tetrahydrofurfuryl 3525.9 47.3 33.52 alcohol) 25 31.5 60.2 22.42 12.5 48.6 80.6 8.20 p-XyleneBis (n- 25 20.5 24.6 58.86 20.45 ± 1.76  butylxanthate) 20 35.2 57.624.51 15 62.4 84.3 5.97 10 57.3 90.2 2.59 m-Fluorobenzyl 25 12.5 32.848.67 19.65 ± 2.99  isobutylxanthate 20 24.7 53.6 27.86 15 33.24 68.716.07 10 50.4 75.2 11.63

[0087] Data represented as the mean of five replicates in threedifferent sets of experiments.${A \cdot I} = {{{Anti}\text{-}{feedent}\quad {index}} = {\begin{matrix}{\left( {{Control}\quad {consumption}} \right) - \left( {{Treated}\quad {consumption}} \right)} \\{\left( {{Control}\quad {consumption}} \right) + \left( {{Treated}\quad {consumption}} \right)}\end{matrix} \times 100}}$

[0088] Normal and control worms consumed 45-50% leaf in 12 hours and87-95% leaf consumption in 24 hours.

[0089] It is concluded that the above alkyixanthates have exhibitedsimilar kind of mode of action as Azadiractin. Though alkyixanthateshave less active than Azadiractin but they can be very easilysynthasized and possessing quick biodegradability. The above resultswere obtained through oral feeding. Similar activities were alsoobserved when these larvae were treated topically with known amount ofcompounds, These experiments are also conformed that the mode of actionis similar to Azadiractin.

[0090] Bio-evaluations on Helicoverpa armigera (an Agricultural pest)Topical application of analogues)

[0091] Our earlier studies exhibited the analogues of alkylxanthates asan antifeedents and insect growth regulator properties againstagricultural pest Spodoptera litura.

[0092] Further experiments were performed on Helicoverpa armigera(Hubner), a lepidopteron pest was used as an experimental modal toreconfirm the IGR activities of alkylxanthates. Once again the presentresults provide that the importance of these compounds as potentialcandidates as Insect Growth Regulators (IGR) against lepidopteron pests.The activity of Azadiractin (standard compound) and alkylxanthates has asimilar mode of action i.e., less larvicidal activity, minimized in theformation of normal pupae and emergence of normal adults.

[0093] The genera Helicoverpa (eliothis) is one of the most importantLepidopteron pest of both subsistence and cash crops in the new and oldworlds. Helicoverpa armigera (Hubner), commonly referred to as theAmerican bollworm or gram pod borer, is the most widely distributed ofthe group occurring in Africa, Asia, Australia, Oceania and Europe. Thepolyphagous larvae attack cotton, maize, sorghum, sunflower, tomato,okra and a range of legumes.

[0094] In India, annual loses to pigeonpea and chickpea alone may exceedUS$ 300 million (Reed and power, 1982), and a more recent estimate byMehrotra (Indian Agricultural Research Institute, unpublished) suggeststhat total loses to pluses and cotton are likely to be more than US$ 530million per annum. No. Adult emergence Conc. Insects Larval PUPALFORMATION Non Sample (μg/ used for mortality Normal Abnormal PupalNormal Abnormal Inter- emer- Code Insect) assay (%) pupa Pupa Mortalityadults adults mediates gence Methylene Bis (n- 100 20 × 5 61 -0- 22 17-0- -0- -2- 20 butylxanthate) 75 20 × 5 49 -0- 27 24 -0- -1- -2- 24 5020 × 5 28 12 32 28 -8- -9- -6- 21 35 20 × 5 12 27 28 33 17 11 18 -9- 2020 × 5 -7- 52 36 -5- 27 41 17 -3- O,O-diethyl 100 25 × 4 92 -0- -6- -3--0- -1- -0- -5- thiophospate 75 25 × 4 85 -3- -5- -7- -4- -1- -0- -3-phenethyl 50 25 × 4 71 -5- 11 -9- -5- -7- -2- -2- xanthate 35 25 × 4 6212 15 11 -9- 16 -4- -8- 25 25 × 4 47 23 13 17 15 -7- -5- -9- p-XyleneBis (n- 100 20 × 5 85 -0- -6- 15 -0- -1- -1- -4- butylxanthate) 75 20 ×5 71 -5- -7- 17 -0- -2- -2- -8- 50 20 × 5 56 10 13 21 -9- 13 -3- -4- 3520 × 5 42 12 18 28 -9- 12 -3- -6- 20 20 × 5 18 39 27 16 33 19 -7- -5-Control 100 25 × 4  3 97 -0- -0- 94 -0- -0- -3- Azadiractin 50 25 × 4 91-0- -5- -4- -0- -2- -2- -1- 35 25 × 4 68 -8- 12 12 -2- -6- -4- -3- 20 25× 4 47 13 27 13 10 17 -5- -8- 10 25 × 4 26 33 23 18 18 21 10 -7- 5 25 ×4 11 47 32 11 38 18 20 -2- 2.5 25 × 4 -2- 62 28 -8- 51 26 13 -0-

[0095] The analogues of alkyixanthates has been proved as insect growthregulates (IGR) against two different lepidopteron pests as similar toAzadiractin (standard compound) a natural product isolated from neemseed kernel They have simple structures unlike Azadiractin andpossessing same kind of mode of action which can be synthesized easilyin the laboratory.

[0096] VI. Bio-evaluations on Agricultural pest Spodoptera litura(Topical application of xanthate analogues) No. Adult emergence Conc.insects Larval PUPAL FORMATION Non Sample (μg/ used for mortality NormalAbnormal Pupal Normal Abnormal Inter- emer- Code Insect) assay (%) pupaPupa Mortality adults adults mediates gence Methylene bis (n- 100 20 × 586 -0- 14 14 -0- -0- -0- 14 butylxanthate) 75 20 × 5 72 -0- 28 25 -0--1- -2- 25 50 20 × 5 57  5 38 24  5  6  8  9 35 20 × 5 21 25 54 26  7 2323 25 20 20 × 5  0 47 53 17 24 27 32 -2- 10 20 × 5  0 52 48 -8- 36 22 34-1- 5 20 × 5  0 59 41 -5- 41 26 28 -0- M-Fluoro benzyl 100 20 × 5 96 -0--4- -4- -0- -0- -0- -0- isobutyl 75 20 × 5 83 -9- -8- 13 -0- -3- -1- -2-xanthate 50 20 × 5 70 13 15 -9- -3- 11 -5- -4- 35 20 × 5 56 25 19 -7- 1714 -6- -0- 25 20 × 5 27 43 30 -4- 39 22 -8- -0- 10 20 × 5 10 58 32 -8-49 29 -4- -1- 5 20 × 5  3 73 24 -3- 50 32 -2- -0- Methylene bis 100 25 ×4 98 -0- -2- -1- -0- -1- -0- -0- (tetrahydrofurfury 75 25 × 4 91 -2- -7--5- -2- -2- -0- -2- lxanthate 50 25 × 4 80 -7- 13 -4- -4- -9- -3- -1- 3525 × 4 71 19 10 -7- -9- 11 -2- -3- 25 25 × 4 59 25 16 -7- 15 17 -2- -2-10 25 × 4 46 44 10 -6- 28 19 -1- -2- 5 25 × 4 36 58  6 -5- 37 22 -0- -3-p-Xylene bis (n- 100 20 × 5 95 -0- -5- -4- -0- -0- -1- -2-butylxanthate) 75 20 × 5 86 -3- -11- 10 -0- -2- -2- -2- 50 20 × 5 71 -8-21 14 -2- 13 -3- -1- 35 20 × 5 59 12 29 13 -9- 17 -2- -4- 20 20 × 5 2059 21 -5- 25 36 -14- -5- 10 20 × 5  5 72 23 -3- 44 38 10 -1- 5 20 × 5  085 15 -2- 59 29 10 -0- Control 100 25 × 4  5 95 -0- -0- 94 -0- -0- -1-Standard 75 25 × 4 96 -0- -4- -4- -0- -0- -0- -0- Azadiractin 50 25 × 488 -7- -5- -8- -0- -2- -2- -1- 35 25 × 4 72 -10- 18 16 -2- -6- -4- -2-20 25 × 4 52 19 29 10 10 17 11 -3- 10 25 × 4 30 38 32 -7- 28 21 14 -1- 525 × 4 -9- 45 34 11 38 19 20 -2- 2.5 25 × 4 -0- 62 38 -6- 47 26 21 -6-

1. Novel compounds of alkylxanthates namely (i) methylene Bis(tetrahydrofurfuryl xanthate) (ii) m -Fluorobenzyl n-butylxanthate and(iii) m-Fluorobenyl isobutylxanthate having the structural formulae asshown in FIGS. 1, 2 and 3 respectively of the accompanying drawings, foruse in agricultural applications.
 2. Novel compounds as claimed in claim1 wherein, said compounds having the following properties onlepidopteron pest as (d) larvicidal, (e) antifeedant, and (f) insectgrowth regulator.
 3. Novel compounds as claimed in claim 1 possesstoxicity towards brine shrimp and mosquitoes.
 4. Novel compounds asclaimed claim 1 controls the growth of the agricultural pests isSpodoptera litura, Helicover armigera.
 5. Novel compounds as claimedclaim 1, wherein the amount of alkylxanthates used as insect growthregulator is ranging from 50 μg to 100 μg per insect, (topicalapplication on III instar larvae) and 5 to 25 μg oral feeding.
 6. Novelcompounds as claimed claim 1, wherein the larval mortality rate is inthe range between 50 to 90%.
 7. Novel compounds as claimed in claim 1wherein, the amount of analogues of alkyl xanthates used for protectingthe leafs are in the range between 15 to 50 micro grams per sq.cm of theleaf area.
 8. Novel compound methylene Bis (tetrahydrofurfuryl xanthate)as claimed in claim 1, is a colorless liquid and the molecular formulais C₁₃H₂₀O₄S₄.
 9. Novel compound m-fluorobenzyl n-butylxanthate asclaimed in claim 1, is a pale yellow liquid having molecular formulaC₁₂H₁₅FOS₂.
 10. Novel compound m-fluorobenzyl isobutylxanthate asclaimed in claim 1 is a pale yellow liquid and having molecular formulaC₁₂H₁₅FOS₂.
 11. New use of analogues of alkylxanthates of formulae 1 to6 of the drawings as insect growth regulators for the integrated pestmanagement (IPM).
 12. Use as claimed claim 11 wherein, the analogues ofalkyixanthates used are ethylene bis(isobutyl xanthate), methylene bis(n-butyl xanthate), methylene bis (tetrafurfurylxanthate), p-xylene bis(n-butylxanthate) and m-Fluorobenzyl isobutylxanthate, the structuralformulae of the above compounds are shown in the FIGS. 4, 5, 1, 6, 2 and3 of the drawings respectively.
 13. Use as claimed claim 12 wherein, thealkyl xanthate controls the growth of the agricultural pests isSpodoptera litura, Helicover armigera.
 14. Use as claimed claim 12.wherein, the amount of alkylxanthates used as insect growth regulator isranging from 50 μg to 100 μg per insect.(topical application on IIIinstar larvae) and 5 to 25 μg oral feeding.
 15. Use as claimed in claim12 wherein, the larval mortality rate is in the range between 50 to 90%16. New use of analogues of alkylxanthates as an antifeedant for theintegrated pest management.
 17. Use as claimed in claim 16 wherein, theamount of analogues of alkyl xanthates used for protecting the leafs arein the range between 15 to 50 micro grams per sq.cm of the leaf area 18.Use as claimed claim 16 where the analogues of alkylxanthates used areethylene bis(isobutyl xanthate),methylene bis (n-butyl xanthate),methylene bis (tetrafurfurylxanthate), p-xylene bis (n-butyl xanthate)and m-Fluorobenzyl n-butylxanthate and m-Fluorobenyl isobutylxanthate.19. Use as claimed claim 16 wherein, the alkyl xanthate acts against theploy phagous pests, spodotera litura (Tabaco caterpillar) and controlsthe consumption of the leaf by the pests.
 20. A process for thepreparation of analogues of alkyl xanthates useful as an antifeedant andas insect growth regulators, said process comprising: a. refluxing KOHwith an alcohol followed by adding carbondisulphide to get a yellowcrystalline compound namely potassium —O-alkylxanthate, b. reacting thepotassium-O-alkylxanthate in the presence of ketone with a bromidederivative selected from methylene di bromide, ethylene di bromide,p-Xylene dibromide or m-flurobenzyl bromide, filtering and removing thecompounds with the yield ranging from 70 to 80%.
 21. A process asclaimed in claim 20 wherein, the refluxing is carried out at a 0° C. 22.A novel composition used as an insect growth regulator and anantifeedant for the integrated pest management, said compositioncomprising an effective amount of alkylxanthate and analogues ofalkylxanthates with an additive.
 23. A composition as claimed in claim22 wherein, the analogues of alkyl xanthate is selected from ethylenebis(isobutyl xanthate), methylene bis (n-butyl xanthate), methylene bis(tetrahydrofurfuryl xanthate), p-xylene bis (n-butyl xanthate),m-Fluorobenzyl n-butylxanthate and m-Fluorobenzyl isobutylxanthate ormixture thereof.
 24. A composition as claimed in claim 22 wherein, theadditive is a solvent, i.e. C₉, cycloxonone, acetone, ethyl methylketone etc., with emulsifier piperonyl butoxide (5%)
 25. A compositionas claimed in claim 22 wherein, the ratio of the additive to the activeingredients is in the ratio ranging from 80 to 95%.
 26. A composition asclaimed in claim 22 wherein, the amount required for controlling theantifeedant activity is 30 to 60 μg/sq.cm.
 27. A composition as claimedin claim 22 wherein, the amount required for use as insect growthregulators activity is 50 to 100 μg/insect (Topical) or 5 to 25 μg oralfeeding.